Andrew b



(1110 Model.)

' J.v MUIRHEAD.

BIT., No. 562,479. l PatentedJune 23,1896i Y .wie *uq l Bv a, i

UNiTnnSrAri-:s PATENT Carien;

i Jol-1N MUIRHEAD, or PrrTsToN, PENNSYLVANIA.

BIT.

SPECIFICATION forming part of Letters Patent No. 562,479, dated June 23,1896.

Application led March 7, 1896.

To a/ZZ whom it may concern:

Be it known that I, JOHN MUIRHEAD, a citizen of the United States,residing at Pittston, in the county of Luzerne, State of Pennsylvania,have `invented a new and useful Improvement in Bits or Drills, whichimprovement is fully set forth in the following speciiication andaccompanying drawings. A

My invention consists of a novel construction of a bit for drilling, thesame being made in sections which are locked together by a tongueand-groove extending longitudinally i of the abutting edges for aportion of their length, wherebyA provision is made for Aenabling a bitof large size to be readily manufactured and assembled, and in case ofbreakage or injury to one section of the same, the damaged member can bereadily removed and replaced without necessitating the loss of theentire bit,

It further consists of novel details of construction, all as will behereinafter set forth, and specifically pointed out in the claim.

Figure l represents a plan view of a bit embodying my invention. Fig. 2represents a side view of the same. Fig. 3 represents a section on linea: Fig. 1, viewed in the direction of the arrows. Fig. i represents anend view of the bit viewed from the cutting edge.

Fig. 5 represents an end view of the bit viewed from the opposite orshank end. Fig. 6 represents a view similar to Fig. 3, showing thesections of the bit in detached position. Fig. 7 represents a section online y fg, Fig. 1 viewed in the direction of the arrows.

Similar letters of reference indicate corresponding parts in the severalfigures.

Referring to the drawings, A designates a bit, the same being composedof the sections B and C, of equal length, which are each provided with ahead D, a shank E, the body portion F, and the tongue and groove K andL, common to the abutting faces of each section, it being noted thatsaid tongue and groove extend longitudinally from the shank to abouthalf-way the length of the bit, as indicated in dotted lines in Fig. l.

The body portion F of the bit is provided with recesses Gon either side,which extend from about midway the length of the bit to its cutting edgeJ, as will be understood from Figs. l and 2, the said recessesterminating a short distance from the edges of the bit,

serial No. 582,194. (No mail4 thereby producing the raised portions orribs H,which serve to greatly increaseV the strength of the bit, as willbe understood from Figs. 4 and '7.

The manner of assembling the parts is as follows `The sections B and Care formed separately and provided with the tongue and groove K and L,respectively, the extent of which will be readily understood from Figs.1 and 2, the same extending from the shank E to near the beginning ofthe recess G, it being noted that the abutting faces from thetermination of the tongue and groove to the cutting edge J are devoid oflocking devices, although of course it will be evident that said tongueand groove may extend throughout the length of the bit, if desired. Thesaid sections B and C having been assembled, as indicated in Fig. 3, andlocked in position by means of the tongue and groove, are then finishedup, the head D being turned to the requisite diameter and the shank Eprovided with threads thereon for the purpose of engagement with asuitable socket.

It will thus be seen from the foregoing that an exceedingly strong,durable, and effective bit is produced, and one which is not liable tobreak or become damaged under any conditions, it being furthermoreapparent that when one section becomes broken or damaged in any way thesame can be removed and a new one substituted in place thereof atcomparatively slight expense, as compared with the loss of the wholebit, as would be the case if the saine were made solid or integral asheretofore.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

A bit consisting of the sections B and C, the same having a head Dthereon, the shank E, the body portion F, the recessed opposite faces G,the strengthening-ribs H, and the cutting edge J, the abutting faces ofsaid sections being provided with a locking device composed of a tongueand groove K and L extending from said shank end to near the center ofthe body thereof, substantially as described.

JOHN MUIRHEAD..

Vitnesses:

F. I-I. KYTE, P. AL GIBBoNs.

IOO

